In the early hours of Thursday, ashes from the Turrialba Volcano, located 67 kilometers northeast of the Costa Rican capital, spread to several locations in the Central Valley, the Seismological and Volcanological Observatory of Costa Rica (OVSICORI) reported. Scientists recorded a strong emission of ash and gas at about 3 a.m. accompanied by seismic activity.

According to OVSICORI, a pilot from a Taca Airlines flight reported to the Civil Aviation Authority a “big cloud of gas and ash coming out of the crater.” The flight was headed to Panama City and the pilot spotted the cloud shortly after 6 a.m. south of the volcano, at an altitude of about 4,000 meters (13,000 feet).

OVSICORI urged Facebook users to collect ash samples in plastic bags from today’s explosion and contact them via a private message on the social media network.

Although the emission of volcanic material has continued since a large explosion on Oct. 29, experts have said Turrialba’s activity has steadily decreased since then. Explosions have reshaped the volcano, and rains in recent days have formed a lagoon in its crater.

In the past 3,500 years, the Turrialba Volcano has seen at least six large eruptions, according to OVSICORI.

The Turrialba Volcano, 67 km northeast of Costa Rica's capital, continued spewing ash and gas on Thursday. But scientists said the volcanic activity there has decreased since a large explosion in late October. (Courtesy of OVSICORI)